Pulsating LED

In this project we make a pulsating LED by adjusting the brightness. The LED pulsates on and off. The brightness changes by PWM. The PWM is a made by the software instead of hardware. The circuit is simply a LED connected to pin0 of PORTB and ground via a current limiting resistor.

Because it is a software PWM, the LED can be connected to any pin. The circuit can be build with the ATMega328 board and a breadboard. The ATMega328 board can be purchased at www.bizztronix.eu. A hyperflux LED is used, this LED draws 20mA current and is very bright. Get a piece of paper of about A6 size (10cm by 15cm), roll it into a cylinder, then glue the edges together so it remains that way. Then place the cylinder over the top of the LED. This will diffuse the light from the LED.